The Wound Healing Effects of Adiponectin Eye Drops after Corneal Alkali Burn.

ABSTRACT

PURPOSE: To investigate the wound healing effect of adiponectin eye drops following corneal alkali burn. MATERIALS AND METHODS: A chemical burn was induced using 0.1 M NaOH in both adenovirus 12-SV40 hybrid-transformed human corneal epithelial (HCE-2) cells and C57BL/6 mice. The injured HCE-2 and mice were then treated using either 0.1% hyaluronic acid (HA) or adiponectin at 0.0001%, 0.001%, or 0.01% concentration. The viability of the HCE-2 cells was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The wound healing rate of the HCE-2 cells was evaluated using a migration assay 4, 8, 12, 24, and 48 h after chemical injury. In mice, corneal epithelial defects and degree of haze were analyzed 6 h and 1, 2, 3, 6, and 7 days after chemical injury. Seven days after injury, the concentrations of IL-1ß and transforming growth factor-ß (TGF-ß) in the cornea were measured using enzyme-linked immunosorbent assay, and histological analysis was also performed. RESULTS: The viability of HCE-2 cells was not affected by adiponectin at any of the concentrations used. In HCE-2 cells treated using either 0.001% or 0.01% adiponectin, the wound healing rate after 4 h was significantly faster than in the control and HA-treated groups. With regard to mice, the 0.001% and 0.01% adiponectin-treated groups showed a significant improvement in epithelial defect parameters and haze scores at 3, 5, and 7 days after chemical injury. A significant decrease in IL-1ß and TGF-ß levels was observed in the 0.001% and 0.01% adiponectin-treated groups compared to the other groups. Histologically, corneal thickness and the inflammatory cells were also decreased in the adiponectin-treated groups. CONCLUSIONS: Topical adiponectin (both 0.001% and 0.01%) increased epithelial migration and improved clinical signs and inflammation on the ocular surface after alkali burn, suggesting that adiponectin can promote wound healing in the cornea.